Propane tankless water heater

[etpm]

Over the holidays I spent a couple days at my sister in law's place. She has a propane fired tankless water heater and I really like it. Since I need to replace my water heater I am gonna go tankless. Her's works great, has done so for over 7 years, temperature control is just like my tanked water heater and two showers can be running at the same time. I have a small amount of minerals in my well water so may need to install a filter. I don't know yet what brand and BTU rating her's is but will find out. Any comments?
Eric

 

[Dan Hunter]

Make sure your inputs/outputs match your unit. I tried to replace tank gas water heater in my now 25 year old home and at the time nothing was compatible.

 

[2manyrocks]

You will need to see if your present vent is sized large enough to handle the tankless.

 

[etpm]

Make sure your inputs/outputs match your unit. I tried to replace tank gas water heater in my now 25 year old home and at the time nothing was compatible.

What do you mean, the water pipes? That's no problem. I have plenty of room to adjust pipe locations.
Eric

 

[Dan Hunter]

The internal size of the pipes in your hose. Hey, it's been a while; maybe it's nothing.

 

[etpm]

You will need to see if your present vent is sized large enough to handle the tankless.

Yeah, I thought about that, but I think it's fine for size. I can enlarge it if need be.
Thanks,
Eric

 

[IXLR8]

I have a tankless water heater, 200,000 BTU's, I hate it. Once the hot water reaches the point of use, it goes on forever, but in general it takes over a minute to get hot water to any faucet. It takes at least 30 seconds before there is warm water coming out of the unit. I put in a recirculating system and that takes care of most of the delays, if you remember to turn it on.

 

[LittleBill21]

gas requirements will probably need to be upsized. make sure you understand the flow rates of these things and your current water temperature, and the GPM you want.

 

[duffer]

I've had tankless heaters for the past 15 yrs. I'll never go back to the old type. endless hot water, consistent temps, all's good.

I'm partial to Rinnai brand. Have had great luck with them. No issues at all. Got the 95k outdoor model. You can run 3 showers, and a dishwasher at the same time. (9 gal/min)

Re: minerals. There are some good YT video's on how to flush/clean your system any time you want. I've done mine a couple of times and its a piece of cake.

Unless you're a very good plumber, I'd suggest you hire the installation done by a pro. There are LOTS of fittings and logistics that need to be considered. If you can, get the outdoor model. Easier install, less expensive (no interior intake/exhaust pipe..$$$). Locate in the middle of the house if possible, or next to the master bath.

One other suggestion: Put an elec outlet under the unit, "inside" the lower cavity. It's handy when flushing the system, as well as having a "heat light" when needed on sub-freezing temps.

 

[Racer4]

I put a Navien combination boiler in about 10 years ago. Does tankless hot water and heats the house.

It’s true about taking a while before getting hot water to the tap, especially in the summer. In winter, the water gets hot fast because the unit is already hot from heating the house.

Some water heaters only models have a small buffering tank inside that is kept hot all the time.

 

[Tinhack]

I have a small amount of minerals in my well water so may need to install a filter.

Filters don't do anything to remove dissolved minerals (Total Dissolved Solids). I put carbon filters on my ice and drinking water tap and found out the water going in had the same TDS as the water coming out of the filter. To lower the TDS, you need a water conditioner or ion exchanger. These are sometimes called water softeners because they lower the hardness or TDS. I didn't think it was worth it for just ice and drinking water and certainly not for the whole house. YMMV.

 

[dstig1]

They are great overall but VERY sensitive to hard water. You pretty much require a softener set up that is always maintained. I found out the hard way (pun intended) as I have pretty hard water and did not immediately set up the softener as I had too many other things going on. We moved in and were using the water fully hard and it killed the heater in the space of a few months. Got the softener installed and replaced the heater. Fine for the past 9 years now.

You will need to look into gas supply requirements as they can require some serious flow which means bigger pipes than you may think (not crazy big, but bigger). And also sort out air intake and exhaust. Download the manual from the ones you are considering and do a little research. Supplyhouse.com is the greatest place to buy from online and they have all the manuals readily available.

 

[ponytug]

Over the holidays I spent a couple days at my sister in law's place. She has a propane fired tankless water heater and I really like it. Since I need to replace my water heater I am gonna go tankless. Her's works great, has done so for over 7 years, temperature control is just like my tanked water heater and two showers can be running at the same time. I have a small amount of minerals in my well water so may need to install a filter. I don't know yet what brand and BTU rating her's is but will find out. Any comments?
Eric

Another vote to double check your propane regulator, pipes, and pressure. 200kBTUs is much more than many whole house furnaces, and you may need to upgrade the regulator at the tank, and may need one or two secondary regulators.

As @duffer wrote, if you can locate the tankless heater in the center of the hot water usage, it will work better. If you can switch to PEX pipes at the same time, PEX has a smaller internal diameter, and therefore lower dead volume, so a faster time to hot water. Personally, I would not put an outlet under a tankless water heater, (Sooner or later it will leak.), but I would put one nearby.

If you can, I would try to get a tankless with a built in recirculating pump, as it saves the wait for water.

Personally, I am not fan of central tankless water heaters; I hate to wait for hot water, I dislike letting water run down the drain, and tankless water heaters have stringent requirements for water quality. If you have any salt (chloride) in your water, the heat exchangers (copper and stainless steel both) corrode. I would vote for a heat pump water heater; just don't put it in the house. Even the quiet ones usually sound louder than a refrigerator. (FWIW: AO Smith heat pumps don't work below 37F)

All the best,

Peter

 

[etpm]

Lotsa good info folks, I really appreciate it. I have dissolved minerals of course, though no alot. But I do have solid minerals, tiny particles that collect on the bottom of the toilet tanks and sometimes collect in the kitchen sink faucet screen. I will for sure need to talk to my propane supplier about gas supply. The tank is close to the house so I'm sure getting a higher gas flow will be easy to accomplish.
Eric

 

[ponytug]

Lotsa good info folks, I really appreciate it. I have dissolved minerals of course, though no alot. But I do have solid minerals, tiny particles that collect on the bottom of the toilet tanks and sometimes collect in the kitchen sink faucet screen. I will for sure need to talk to my propane supplier about gas supply. The tank is close to the house so I'm sure getting a higher gas flow will be easy to accomplish.
Eric

Whole house water filters or just a large water filter ahead of the tankless should help keep a tankless from being bothered with that. You might consider an upstream "spin-down" sediment filters upstream of the finer filter. Spindowns can drain sediment pretty easily without changing the filter, especially if you can plumb in a backflush. (E.g. after your well/booster pump, but before your pressure tank.) I have used the Rusco (sp?) brand in the past; you can get different mesh filters depending on the size of the sediment you are targeting.

All the best,

Peter

 

[kenmac]

You will need to see if your present vent is sized large enough to handle the tankless.

tankless will not use the same type, or size vent

 

[kenmac]

Over the holidays I spent a couple days at my sister in law's place. She has a propane fired tankless water heater and I really like it. Since I need to replace my water heater I am gonna go tankless. Her's works great, has done so for over 7 years, temperature control is just like my tanked water heater and two showers can be running at the same time. I have a small amount of minerals in my well water so may need to install a filter. I don't know yet what brand and BTU rating her's is but will find out. Any comments?
Eric

inlet filter will help some. But as the water is heated, the minerals that are in the water will separate from the water and attach it's self to the water coil. You may have to flush the coil more than normal to prevent total blockage of the water coil.

I have attended several classes where they had cut aways of water coils completely blocked from mineral deposits. so I recommend a good flush depending on water quality

 

[WinterDeere]

I have an old friend who installed a Rinnai tankless, when we were living next door to one another, and always helping each other with renovations. He loves it, but...

1. He will be the first to tell you that the wait for hot water is noticeably longer.

2. BTU requirement usually means the typical 1/2 psi propane regulator installed outdoors will need to be swapped to 2 psi, and then separate 1/2 psi regulators installed where water heater tees off from the remaining appliances. Your other option is to upgrade line sizes and stay at 1/2 psi, but this is usually more expensive and challenging than just running the higher pressure, to increase delivered volume.

3. They're very sensitive to hard water build-up. He was on a softener, and maintained it religiously, so no issue. But some recommend not installing downstream of a softener, which is one of those "damned if you do / damned if you don't", situations. I do think he had a carbon filter after his softener, and before the water heater, as I remember copying that on my ice maker. Not sure how much difference it makes, he never had any issues.

Even with all that, he says he'll never go back to a tank.

 

[kenmac]

Lotsa good info folks, I really appreciate it. I have dissolved minerals of course, though no alot. But I do have solid minerals, tiny particles that collect on the bottom of the toilet tanks and sometimes collect in the kitchen sink faucet screen. I will for sure need to talk to my propane supplier about gas supply. The tank is close to the house so I'm sure getting a higher gas flow will be easy to accomplish.
Eric

most of these tankless burn 199,900 BTU. If that's the one you purchase. make sure you have plenty of supply /volume to handle that many BTU. depending on distance, 3/4-1'' black iron gas pipe. You'll be burning on 11'' WC with the propane

 

[kenmac]

another thing is. Make sure the one you purchase comes with flush valves. some do and some don't. You'll need these when it comes time to flush the WH